The 3GPP (Third Generation Partnership Project), which is a standardization project, has standardized Evolved Universal Terrestrial Radio Access (hereinafter referred to as “E-UTRA”), which achieves high-speed communications, by the adoption of the OFDM (orthogonal frequency-division multiplexing) communication scheme and flexible scheduling in predetermined units of frequency and time called resource blocks.
Further, the 3GPP is also working on the standardization of an evolutionary extension of E-UTRA, i.e., Advanced E-UTRA. Advanced E-UTRA envisages using a band up to a maximum bandwidth of 100 MHz for the uplink and the downlink alike to perform communications at maximum transmission rates of 1 Gbps or higher in the downlink and 500 Mbps or higher in the uplink.
Advanced E-UTRA is discussing Heterogeneous Network (hereinafter referred to as “HetNet”) for efficient processing of locally generated communication traffic. HetNet is, in addition to conventional micro cells, a layered network in which small cells such as picocells and femtocells are placed so that cell areas are overlapped with macrocells (in the same frequencies or different frequencies). HetNet makes it possible to distribute communication traffic by transferring communications between terminal apparatuses near a small cell serving in a macrocell into the small cell. Therefore, the 3GPP is discussing a mechanism in which a terminal apparatus serving in a macrocell can efficiently detect and camp a small cell (NPL 1).
In a HetNet environment, the use (connection) of a small cell by (to) a terminal apparatus moving at a high speed may cause frequent occurrence of handover and thus undesirably increase signaling overhead. In view of this problem, NPL 2 discloses that at the time of RRC connection, a terminal apparatus notifies a base station apparatus of information concerning a mobility state of the terminal apparatus, whereby mobility control can be performed so that the base station apparatus does not hand over a rapidly moving terminal apparatus to a small cell.